1. Field of the Invention
Priority is claimed on Japanese Patent Application No. 2010-198167, filed Sep. 3, 2010, the contents of which are incorporated herein by reference.
The present invention relates to an inattention determining device.
2. Description of Related Art
A face direction angle is detected on the basis of a face image obtained by capturing an image of a driver's face. A device, which changes an angle threshold value as reference when determining inattention using the face direction angle on the basis of the velocity of a vehicle, a yaw rate, or a lateral acceleration according to a driving state (for example, a curve driving state) of the vehicle, is described in Japanese Unexamined Patent Application, First Publication No. 2009-294753.
According to the device of the related art, after detecting the yaw rate or the lateral acceleration generated when the driving state of the vehicle is actually changed, the angle threshold value is changed.
However, the driver generally performs an action of visually checking a forward turning direction from a state of driving straight on a straight path before entering the curve. Accordingly, when the angle threshold value is changed after entering the curve as the technique described in the related art, the change of the angle threshold value occurs too late, and the determination of inattention is incorrectly performed. That is, the device of the related art may erroneously determine that the state of visually checking the turning direction of the forward curve in the state of driving straight on the straight way before entering the curve is an inattention state.
It is desirable to provide an inattention device capable of appropriately determining inattention of a driver.